Biz
12-27-2021, 07:14 PM
I did some experiments on my new mainline today, to make sure I could pull good vacuum on it using a diaphragm pump.
Mainline is 280' line, 3/4" diameter. It is 10' or less elevation change end to end but set up tight with no sags or flat runs. Only one saddle total with adaptor to a vacuum gauge, no laterals. The gauge was used at the far end of the line and only shows vacuum in test 3. I have a ball valve at the 100' mark and one at 200'. Obviously this system is very tight since there are no laterals and only one saddle. The goal was to make sure that there isn't a basic problem pulling vacuum in this setup, if everything is really tight. I had heard from some customers with mainlines that they were unable to pull good vacuum with the diaphragm pumps, so I wanted to see for myself if the setup inherently works if there are no leaks.
I used a Shurflo 4048 pump and a recirculation line. No liquid flowed through the mainline, but this seems like it replicates a working mainline since I have flow through the pump and have the mainline volume.
First test was to close the first valve so there was 100' of mainline connected to the pump.
Second test, first valve open and second closed so I had 200' on mainline connected.
Third test, both valves open so I had nearly 300' connected. A Mountain Maple S4 controller was used for vacuum measurement at the pump and to measure operating time. As a baseline test, I measured 24" of vacuum within a couple minutes with just the recirculation line attached.
I was going to try smaller and larger pumps but perhaps a later time.
Now for the results.
1. 100' mainline: Reached 20" of vacuum in 4 minutes, 22-23" in 10 minutes, 24" in 13 minutes. Cool, it works :)
2. 200' mainline: Reached 18" of vacuum in 4 minutes, 20" in 8 minutes, and maxed out around 23" in 22 minutes. It might have reached 24" eventually, but those last couple of inches take a long time with increased mainline length.
3. 280' mainline: Reached 15" of vacuum in 4 minutes, 20" in 10 minutes, 21" in 15 minutes, finally hit a steady 23" at the 25 minute mark. The gauge at the end of the line was checked at the 15 minute mark and it matched the vacuum seen at the pump.
When the pump was running, initially there was a LOT of air being pumped through, which reduced as most of the air was drawn from the line over time.
So overall I was pleased that the mainline didn't turn into just an expensive experiment, since the much cheaper 3/16" tubing that this replaced seemed to work pretty well. Too bad I didn't keep better track of how much sap I collected previously to compare. I am definitely going to use a recirculation line on this setup, and I will know that if I do see poor vacuum, it is because of leaks. The ball valves will help in isolating where any leak is coming from. We will find out soon if the test results match reality once I have 50 taps added to the line.
Dave
Mainline is 280' line, 3/4" diameter. It is 10' or less elevation change end to end but set up tight with no sags or flat runs. Only one saddle total with adaptor to a vacuum gauge, no laterals. The gauge was used at the far end of the line and only shows vacuum in test 3. I have a ball valve at the 100' mark and one at 200'. Obviously this system is very tight since there are no laterals and only one saddle. The goal was to make sure that there isn't a basic problem pulling vacuum in this setup, if everything is really tight. I had heard from some customers with mainlines that they were unable to pull good vacuum with the diaphragm pumps, so I wanted to see for myself if the setup inherently works if there are no leaks.
I used a Shurflo 4048 pump and a recirculation line. No liquid flowed through the mainline, but this seems like it replicates a working mainline since I have flow through the pump and have the mainline volume.
First test was to close the first valve so there was 100' of mainline connected to the pump.
Second test, first valve open and second closed so I had 200' on mainline connected.
Third test, both valves open so I had nearly 300' connected. A Mountain Maple S4 controller was used for vacuum measurement at the pump and to measure operating time. As a baseline test, I measured 24" of vacuum within a couple minutes with just the recirculation line attached.
I was going to try smaller and larger pumps but perhaps a later time.
Now for the results.
1. 100' mainline: Reached 20" of vacuum in 4 minutes, 22-23" in 10 minutes, 24" in 13 minutes. Cool, it works :)
2. 200' mainline: Reached 18" of vacuum in 4 minutes, 20" in 8 minutes, and maxed out around 23" in 22 minutes. It might have reached 24" eventually, but those last couple of inches take a long time with increased mainline length.
3. 280' mainline: Reached 15" of vacuum in 4 minutes, 20" in 10 minutes, 21" in 15 minutes, finally hit a steady 23" at the 25 minute mark. The gauge at the end of the line was checked at the 15 minute mark and it matched the vacuum seen at the pump.
When the pump was running, initially there was a LOT of air being pumped through, which reduced as most of the air was drawn from the line over time.
So overall I was pleased that the mainline didn't turn into just an expensive experiment, since the much cheaper 3/16" tubing that this replaced seemed to work pretty well. Too bad I didn't keep better track of how much sap I collected previously to compare. I am definitely going to use a recirculation line on this setup, and I will know that if I do see poor vacuum, it is because of leaks. The ball valves will help in isolating where any leak is coming from. We will find out soon if the test results match reality once I have 50 taps added to the line.
Dave